1. Technical Field
The presently disclosed embodiments are directed to identifying and/or compensating for substrate media edge curl in a printing system.
2. Brief Discussion of Related Art
In production printers using direct marking technology, it is expected that solid inks and ultra violet (UV) gel inks that are jetted directly onto cut sheet media will become increasingly popular. A critical print process parameter for some direct marking printing systems is the print head to substrate media gap, which refers to a distance between print nozzle ejection surface of a print head and the substrate media. In some printing systems, the gap is set to as little as 0.5 millimeter (mm) to minimize the pixel placement errors due to misdirected ink droplets.
These tight printhead to media gaps pose a serious challenge for direct marking printing system, since the lead edge (LE) and trail edge (TE) of the media, and to a less extent the body of the media, are generally not perfectly flat as the media pass by the print heads. For accurate pixel placement and color registration, the print head-to-media gap is desirably kept within about a +/−0.1 mm range about the nominal gap distance. To avoid printhead front face damage, the media must not be allowed to ‘close the gap’ and contact the printhead. Vacuum and electrostatic transport belt technologies are capable of holding down cut sheet media as the media pass the print heads. However, neither technology is typically robust against lead edge and trail edge curl, which refers to substrate media curvature towards the print head and away from the media transport.